The University of Washington proposes a Multidisciplinary Clinical Research Center devoted to the study of spine and upper extremity disorders. These conditions, especially low back pain and carpal tunnel syndrome, are among the most common and disabling conditions in working age populations. This Center will incorporate investigators from the Departments of Medicine, Radiology, Orthopaedics and Sports Medicine, Neurological Surgery, Rehabilitation Medicine, and Psychiatry and Behavioral Sciences in the School of Medicine; and the Departments of Biostatistics and Health Services in the School of Public Health. The Methodology Core will provide key support to each project: assistance with protocol details choice and implementation of outcome measures, central data accumulation, data quality monitoring, analytic strategies, statistical analysis, advice on presentation of results, and education of investigators regarding research architecture and statistical techniques. The projects proposed address key controversies and uncertainties related to spinal disorders and upper extremity complaints. These include: 1. Carpal Tunnel Syndrome. Diagnostic and Treatment Strategies: this incorporates a randomized trial to evaluate the efficacy of surgery for early but well-documented carpal tunnel syndrome, and will determine whether the new technique of MR neurographic imaging (MRNI) accurately identifies the patients most likely to benefit from early surgery. 2. Cohort Study of Treatment for Discogenic Back Pain: a prospective cohort study will compare patients undergoing lumbar arthrodesis for degenerative discogenic pain with those having non-surgical treatments. We seek to identify any differences in baseline characteristics as well as outcomes, and to identify characteristics that may predict unique success from either surgical or non-surgical therapy. 3. Epidemiology of Lumbar Spine Surgery: Rates and Trends: this analysis of national survey data, state hospital discharge registries, and Medicare claims will update the U.S. rates of various forms of back surgery; examine a possible increase in spine fusion rates with the introduction of interbody fusion cages; quantify the shift of spine surgery to the ambulatory setting; and determine if reoperation rates are increasing over time, as suggested in some earlier analyses. 4. Synthesis of CT and MR images of the Cervical Spine: This feasibility project will assess the potential for combining data from CT and MRI scans of the cervical spine to produce more useful imaging for surgical planning purposes than either test alone. It will require computer modeling, based on precedents in MR-PET scanning. We will determine if surgeons will accept the synthesized images as a replacement for CT-myelography for purposes of surgical planning.